Question

A running man has half the kinetic energy as that of a boy of half his mass. The man speeds up by 1 ms^-1 so that the kinetic energies of the boy and man are equal. Calculate the initial speeds of boy and man.

Answer 1

Suppose the mass of the man = m₁ and speed = u₁, mass of the boy m₂ = m₁/n₂ and speed =
Given: In the beginning K_man = \(\frac{1}{2}\) k_boy 

Comparing Eqs (1) and (2), we get